Tablet coating containing a linear poly-1,3-beta-glucoside



United States Patent 3,421,920 TABLET COATING CONTAINING A LINEAR POLY-LS-B-GLUCOSIDE Pravin Sheth, Summit, and Leon Lachman, Millburn,

N.J., assiguors to Ciba Corporation, New York, N.Y.,

a corporation of Delaware No Drawing. Filed May 25, 1965, Ser. No. 458,756 US. Cl. 106-217 9 Claims Int. Cl. C09d 3/10; A61k 3/06 ABSTRACT OF THE DISCLOSURE The solution consisting of (a) a sugar syrup, (b) a hexanehexol, (c) an alkyl sulfosuccinate salt and (d) a linear polyl,3-B-glucoside containing on every third glucose moiety of the chain a 1,6-[t-glucosido group, is useful for direct tablet or candy coating.

The present invention concerns and has for its object the provision of a sugar coating solution useful for the preparation of coated tablets.

For the most part, the sugar coating of medicinal tablets is still performed in accordance with the time-honored procedure whereby a subcoatin-g, a smoothing coating, a finishing coating and a polishing coating are applied to the tablets. These operations and the various drying condi tions required, take about two to four days to finish coating a batch of tablets. in the coated tablets obtained, the weight of the coating usually approximates the weight of the tablet used.

In recent years several attempts have been made, in order to eliminate the shortcomings inherent in the above described procedure. These attempts dealt with two major points, one being the use of lakes or insoluble dyes as colorant in place of water-soluble dyes, and the other being the employment of surfactants, opacifiers and film formers to cause uniform coverage of the sugar coating at reduced thickness. Although these attempts resulted in an about 50% reduction of coating time, they still required some cumbersome subcoating and sealing coating before applying the finishing sugar coating to the tablets.

We have now found a new sugar coating formulation which can be applied directly to tablets without any prior subcoating or smoothing coating operations and which enables one to form elegant and uniform thin film-coated tablets in a total time period ranging between 2 to 3 hours, depending upon the size and shape of the tablets to be coated. This has been accomplished through a physicalchemical approach to the factors governing the crystallization of the ingredients used in said coating formulation, the bonding of the coating to the tablets and the flowout properties or the spreadibility of the coating solution respectively.

Accordingly, the present invention concerns a sugar coating solution comprising in addition to the aqueous sugar solution used, an effective amount of at least:

(a) a hexanehexol (b) a water soluble salt of a higher alkyl sulfosuocinate and (c) a linear poly-1,3-B-glucoside containing on every third glucose moiety of the chain a 1,6a 3-glucosido group.

The sugar solution employed according to the invention is that usually employed for the preparation of coated tablets. it may contain a monoand/ or dis-accharide in the appropriate concentration, but preferably contains sucrose in an amount from about 40 to about 80%, especially from about 50 to 70%.

3,421,920 Patented Jan. 14, 1969 ice The hexanehexol used in the invention is preferably that obtained from natural hexoses by reduction, such as sorbi-tol, dulcitol or especially mannitol.

The water soluble salt of an alkyl sulfosuccinate is preferably an alkali metal or ammonium salt, for example that derived from lithium, potassium or especially sodium, of ammonia or an amine, such as a primary, secondary or tertiary lower alkylamine, e.g. methylamine, ethylamine, propyl'amine, butylamine, dimethylamine, diethylamine, trimethylamine or triethylamine. The higher alkyl residue e'sterifying preferably both of the carboxyl groups present, contains advantageously six to ten carbon atoms, such as 1-, 2- or 3-hexyl, l-heptyl, 1-, 2- or especially 3-octyl, l-nonyl or 4-decyl. Such salts are described, for example, in US. Patent Nos. 2,028,091 and 2,176,423.

The polyglucoside used, mainly has the following formula:

H H on on on o 2 o. n 0 2 2 H o o o o 0 on so so no no on on on on It is sold under the trademark Polytetran and the procedure for making it is found in Belgian Patent No. 639,361, issued Apr. 30, 1964. A preferred form thereof is that of which an 1% aqueous solution shows at 24 C. and in the pH-range between 6.8 and 7.5 a final viscosity (after 5 hours) of about 2400 to 3000 centipoises, measured with a Brookfield viscosimeter using a No. 3 spindle.

The coating solution of this invention contains the hexanehexol in a range of about 1 to 10%, preferably of about 2 to 8%, but especially of about 4 to 6%, the alkyl sulfosucoinate salt in a range of about 0.01 to 0.5%, preferably of about 0.1 to 0.4% but especially of about 0.2 to 0.3%, and the polyglucoside in a range of about 0.01 to 0.2% preferably of about 0.01 to 0.1% but especially of about 0.02 to 0.05%

An especially valuable coating solution contains about 50 to sucrose, about 4 to 6% mannitol, about 0.2 to 0.3% of di-3-octyl sodium succinate and about 0.02 to 0.05% of the polyglucoside.

Besides the above mentioned ingredients, the coating solution of this invention may contain additional ingredients, for example other surfactants, such as monesters of higher fatty acids with polyhydric alcohols or hydroxyethers, such as those described in J. Pharm. 33, 465 et seq. ('1952), opacifiers, such as talc or especially titanium dioxide, and/or dyes, such as those approved and certified under the provisions of the Federal Food, :Drug and Cosmetic Law, and which preferably are insoluble in water.

-In order to obtain elegant sugar coatings, the solution according to the invention is employed in an amount of about 15 to 50%, preferably of about 20 to 30% of the uncoated tablet. tlts use, however, is not limited to pharmaceutical preparations, it may also be used for the coating of confectionary products, e.g. candies, nuts and the like.

The coating procedure is carried out according to known methods, preferably that described in US. Patent No. 3,141,792. The material is placed into the usual coating pan and is sprayed several times with the coating solution of this invention. Between the sprays, the coatings applied to the tablets are dried, preferably by directing heated air into the coating pan. The spraying and drying operations are repeated until the desired coating is obtained. Heat may not be applied to the last coat in order to obtain a smooth surface of the resulting coated tablets. If desired,

they may be polished, preferably with the use of natural waxes, such as bees and carnauba wax, wax mixtures, or synthetic products, such as silicones.

Following are working examples, illustrative of, but in no way intended to limit the present invention. Unless otherwise indicated, all parts, wherever given in the specification, are parts or percentages by weight.

EXAMPLE 1 8 kg. of a coating solution suflicient for 20 kg. of modified ball tablets each weighing 500 mg.

Materials: G.

Sucrose 4800.0 Mannitol 400-.0 Di-3-octyl sodium sulfosuccinate 20.0 Polyglucoside 2.0 Titanium dioxide 40.0 F.D.&C. lake yellow No. 5 4.0 Purified water 2734.0

Procedure The di-3-cotyl sodium sulfosuccinate, sucrose, mannitol and polysaccharide are dissolved in water in this order. Thereupon the lake and titanium dioxide which have been previously milled are added and suspended well by adequate agitation.

kg. of the tablets are placed into a 30 inch coating pan and the above coating solution is sprayed onto the tablets in the manner. 1

Spray:

1-100 ml., 28Gradually increasing from 20 to 130 ml., 933Each 130 ml., 3345Gradually decreasing from 130 to 110 ml. Final-Each 110 ml.

Between the sprays the coatings applied are dried by a stream of air heated to 47 C. After the last spray no hot air is applied and the coated tablets are allowed to dry overnight in a drying cabinet. If desired, they can be polished using, for example, a suitable wax, such as carnauba wax, either as the powder or in solution, for example in carbon tetrachloride, isopropanol or a hydrocarbon.

EXAMPLE 2 10 kg. of a coating solution sufficient for kg. of tablets each weighing 250 mg.

Materials: G.

Sucrose 6000.0 Mannitol 600.0 Di-3-octyl sodium sulfosuccinate 30.0 Polyglucoside 3 .0 Talc 100.0 Purified water 3267.0

Procedure As described in Example 1 by applying an analogous coating cycle.

EXAMPLE 3 10 kg. of a coating solution sufficient for 25 kg. of tablets each weighing 400 mg.

Materials: G.

Sucrose 6000.0 Mannitol 500.0 Di-3-octyl sodium sulfosuccinate 20.0 Polyglucoside 5.0 'F.D.&C. blue No. 2 lake 10.0 Titanium dioxide 50.0 Purified water 3415.0

Procedure Analogous to that shown in Example 1.

4 EXAMPLE 4 10 kg. of a coating solution sutficient for 25 kg. of tablets each weighing 400 mg.

Materials: G.

Sucrose 5500.0 Mannitol 500.0 Di-3-octyl sodium sulfosuccinate 20.0 Polyglucoside 10.0 F.D.&C. blue No. 2 lake 10.0 Tale 500.0 Titanium dioxide 50.0 Purified water 3410.0

Procedure Analogous to that shown in Example 1.

What is claimed is:

1. A sugar coating solution comprising the basic aqueous sugar solution containing the sugar in a range from about 40 to and at least:

(a) about 1 to 10% of a hexanehexol selected from the group consisting of sorbitol, dulcitol and mannitol,

(b) about 0.01 to 0.5% of a water soluble alkali metal or ammonium salt of an alkyl sulfosuccinate containing in the alkyl group 6 to 10 carbon atoms and (c) about 0.01 to 0.2% of a linear poly-1,3-fi-glucoside containing on every third glucose moiety of the chain a 1,6-fi-glucosido group and of which a 1% aqueous solution shows at 24 C. and in the pH-range between 6.8 and 7.5 a final viscosity of about 2400 to 3000 centipoises.

2. A sugar coating solution as claimed in claim 1, containing the sugar in a range from about 50 to 70%, the hexanehexol in a range from about 2 to 8%, the alkyl sulfosuccinate salt in a range from about 0.1 to 0.4% and the polyglucoside in a range of about 0.01 to 0.1%.

3. A sugar coating solution as claimed in claim 1, containing the sugar in a range from about 50 to 70%, the hexanehexol in a range from about 4 to 6%, the alkyl sulfosuccinate salt in a range from about 0.2 to 0.3% and the polyglucoside in a range of about 0.02 to 0.05%.

, 4. A sugar coating solution as claimed in claim 1, wherein the sugar used is sucrose.

5. A sugar coating solution as claimed in claim 1, wherein the hexanehexol used is mannitol.

6. A sugar coating solution as claimed in claim 1. wherein the alkyl sulfosuccinate salt used is di-3-octyl sodium sulfosuccinate.

7. An aqueous sugar coating solution comprising about 50 to 70% sucrose, about 4 to 6% mannitol, about 0.2 to 0.3% di-3-octyl sodium succinate and about 0.02 to 0.05% of a linear poly-1,3-1S-glucoside containing on every third glucose moiety of the chain a 1,6- 3-glucosido group and of which a 1% aqueous solution shows at 24 C. and in the pH-range between 6.8 and 7.5 a final viscosity of about 2400 to 3000 centipoises.

8. A sugar coating solution as claimed in claim 1, containing in addition 0.1 to 2% titanium dioxide and 0.01 to 2% of a lake.

9. The method of coating tablets and confectionary products using the sugar coating solution as claimed in claim 1.

References Cited UNITED STATES PATENTS 2,693,436 11/1954 'Spradling 167-82 2,693,437 11/1954 Spradling 16782 2,925,365 2/1960 Nicholson et a] 167-82 3,185,626 5/1965 Baker 167-82 ALLAN LIEBERMAN, Primary Examiner.

US. Cl. X.R. 

